This revolutionary boresighter will get you on the paper – and much more – faster than ever. Its unique lens aperture system eliminates point of aim errors resulting from parallax due to extreme misalignment. The boresighter also includes natural backlighting of the target, LED illumination for use in low-light settings, and an inch scale for measuring approximate riflescope height and target group sizes. Check your zero. Set new ranges. Compatible with any caliber firearm. Energy efficient design yields 25 hours of battery life. Range cards for recording sight-in information are included. more info